The high energy and power that are found in some laser beams offer a tool for noninvasive alteration of anterior intraocular tissue. specifically, iridotomy and trabeculotomy are possible. This has importance for glaucoma patients because of the potential improvement of surgical outcome and reduced surgical morbidity. The aim of this project is a systematic evaluation of laser effects in simian (rhesus) eyes and the application of promising systems and procedures to human glaucoma eyes under controlled conditions.